This invention relates generally to rotatable machines and more particularly, to methods and systems for in-situ balancing of rotors of rotatable machines.
During the lifetime of a rotating machine, periodic balancing of the rotating member is performed. During operation of a mechanical machine such as a fan or turbine, wear or damage may induce a vibration in the machine. For an electrical machine such as a generator or motor an increase in vibration may be due to copper shorts. Additionally, repair to a rotor such as a rewind or machining may also alter the center of gravity of the rotor resulting in an increase in vibration. To reduce the vibration of the operating machine, an imbalance is quantified and canceling weights are generally attached, removed, or moved on the rotor to counter the imbalance. Typically the rotor is removed from the machine and delivered to a specialized shop with a balance pit or bunker to be balanced. Such maintenance is labor intensive and must generally be scheduled with the balance shop well in advance of the balance procedure. The logistics of transporting a large relatively delicate component also affects the cost and timeliness of an outage when the rotor is to be maintained. Additionally, the process of transporting the rotor carries inherent risks to the health and physical safety of the rotor.